Kevin De Bruyne fears he could miss the rest of the English Premier League title race after tearing his hamstring.
The Manchester City star had to come off during their 1-0 victory over Tottenham Hotspur on Sunday and will now likely be out for their final four league matches.
The midfielder is also struggling to be fit in time for next month's FA Cup final against Watford at Wembley.
Manchester City's Remaining games:
April 24 - Manchester United (Away)
April 28 - Burnley (Away)
May 6 - Leicester (Home)
May 12 - Brighton (Away)
FA CUP FINAL:
May 18 - Watford
De Bruyne had been in a rich vein of form before he suffered another injury setback in City's victory over Spurs at the Etihad.
He was taken off after 38 minutes and is now likely to miss the final four matches of the season.
City boss Pep Guardiola has already ruled him out of Wednesday's crucial trip to Manchester United and tests have reportedly showed he will not be fit to train fully for another two weeks.
That would see him also miss City's upcoming Premier League clashes with Burnley, Leicester and Brighton.
Guardiola's side currently trail league leaders Liverpool by two points but they can secure back-to-back titles with victory in their final four games.
Their task has been made harder by the absence of De Bruyne, who has had terrible luck with injuries this season.
The 27-year-old didn't feature before October and knee-ligament damage saw him make just one Premier League appearance in the first half of the season. Then in March he suffered a hamstring injury that sidelined him for another month.
His latest setback opens the door to Phil Foden to enjoy more first-team action in the final weeks of the season.
Foden scored his first Premier League goal as City beat Spurs just four days after they were dumped out of the Champions League by their rivals.
Fernandinho started on the bench for that game as he battles back to full fitness but he, too, may be forced to play a more prominent role in De Bruyne's absence.